Buggy code:
public class HTTPHC4Impl extends HTTPHCAbstractImpl { private static final Logger log = LoggingManager . getLoggerForClass ( ) ; private static final int RETRY_COUNT = JMeterUtils . getPropDefault ( "httpclient4.retrycount" , 0 ) ; private static final String CONTEXT_METRICS = "jmeter_metrics" ; private static final HttpResponseInterceptor METRICS_SAVER = new HttpResponseInterceptor ( ) { @ Override public void process ( HttpResponse response , HttpContext context ) throws IOException , HttpException { } } ; private static final HttpRequestInterceptor METRICS_RESETTER = new HttpRequestInterceptor ( ) { @ Override public void process ( HttpRequest request , HttpContext context ) throws IOException , HttpException { } } ; private static final ThreadLocal < Map < HTTPHC4Impl . HttpClientKey , HttpClient > > HTTPCLIENTS = new ThreadLocal < Map < HTTPHC4Impl . HttpClientKey , HttpClient > > ( ) { @ Override protected Map < HTTPHC4Impl . HttpClientKey , HttpClient > initialValue ( ) { } } ; private static final Scheme SLOW_HTTP ; private static final Scheme HTTPS_SCHEME ; private static final HttpParams DEFAULT_HTTP_PARAMS ; private volatile HttpUriRequest currentRequest ; private volatile boolean resetSSLContext ; protected HTTPHC4Impl ( HTTPSamplerBase testElement ) { } public static final class HttpDelete extends HttpEntityEnclosingRequestBase { public HttpDelete ( final URI uri ) { } @ Override public String getMethod ( ) { } } @ Override protected HTTPSampleResult sample ( URL url , String method , boolean areFollowingRedirect , int frameDepth ) { HTTPSampleResult res = createSampleResult ( url , method ) ; HttpClient httpClient = setupClient ( url ) ; HttpRequestBase httpRequest = null ; try { URI uri = url . toURI ( ) ; if ( method . equals ( POST ) ) { httpRequest = new HttpPost ( uri ) ; } else if ( method . equals ( PUT ) ) { httpRequest = new HttpPut ( uri ) ; } else if ( method . equals ( HEAD ) ) { httpRequest = new HttpHead ( uri ) ; } else if ( method . equals ( TRACE ) ) { httpRequest = new HttpTrace ( uri ) ; } else if ( method . equals ( OPTIONS ) ) { httpRequest = new HttpOptions ( uri ) ; } else if ( method . equals ( DELETE ) ) { httpRequest = new HTTPHC4Impl . HttpDelete ( uri ) ; } else if ( method . equals ( GET ) ) { httpRequest = new HttpGet ( uri ) ; } else if ( method . equals ( PATCH ) ) { httpRequest = new HttpPatch ( uri ) ; } else { <START_BUG> throw new IllegalArgumentException ( ( "Unexpected<seq2seq4repair_space>method:<seq2seq4repair_space>" + method ) ) ; <END_BUG> } setupRequest ( url , httpRequest , res ) ; } catch ( Exception e ) { res . sampleStart ( ) ; res . sampleEnd ( ) ; errorResult ( e , res ) ; return res ; } HttpContext localContext = new BasicHttpContext ( ) ; res . sampleStart ( ) ; final CacheManager cacheManager = getCacheManager ( ) ; if ( ( cacheManager != null ) && ( GET . equalsIgnoreCase ( method ) ) ) { if ( cacheManager . inCache ( url ) ) { res . sampleEnd ( ) ; res . setResponseNoContent ( ) ; res . setSuccessful ( true ) ; return res ; } } try { currentRequest = httpRequest ; handleMethod ( method , res , httpRequest , localContext ) ; HttpResponse httpResponse = executeRequest ( httpClient , httpRequest , localContext , url ) ; final HttpRequest request = ( ( HttpRequest ) ( localContext . getAttribute ( HTTP_REQUEST ) ) ) ; final InetAddress localAddr = ( ( InetAddress ) ( httpRequest . getParams ( ) . getParameter ( LOCAL_ADDRESS ) ) ) ; if ( localAddr != null ) { request . addHeader ( HEADER_LOCAL_ADDRESS , localAddr . toString ( ) ) ; } res . setRequestHeaders ( getConnectionHeaders ( request ) ) ; Header contentType = httpResponse . getLastHeader ( HEADER_CONTENT_TYPE ) ; if ( contentType != null ) { String ct = contentType . getValue ( ) ; res . setContentType ( ct ) ; res . setEncodingAndType ( ct ) ; } HttpEntity entity = httpResponse . getEntity ( ) ; if ( entity != null ) { InputStream instream = entity . getContent ( ) ; res . setResponseData ( readResponse ( res , instream , ( ( int ) ( entity . getContentLength ( ) ) ) ) ) ; } res . sampleEnd ( ) ; currentRequest = null ; StatusLine statusLine = httpResponse . getStatusLine ( ) ; int statusCode = statusLine . getStatusCode ( ) ; res . setResponseCode ( Integer . toString ( statusCode ) ) ; res . setResponseMessage ( statusLine . getReasonPhrase ( ) ) ; res . setSuccessful ( isSuccessCode ( statusCode ) ) ; res . setResponseHeaders ( getResponseHeaders ( httpResponse ) ) ; if ( res . isRedirect ( ) ) { final Header headerLocation = httpResponse . getLastHeader ( HEADER_LOCATION ) ; if ( headerLocation == null ) { throw new IllegalArgumentException ( "Missing<seq2seq4repair_space>location<seq2seq4repair_space>header" ) ; } try { res . setRedirectLocation ( ConversionUtils . sanitizeUrl ( new URL ( headerLocation . getValue ( ) ) ) . toString ( ) ) ; } catch ( Exception e ) { HTTPHC4Impl . log . error ( ( ( ( "Error<seq2seq4repair_space>sanitizing<seq2seq4repair_space>URL:" + ( headerLocation . getValue ( ) ) ) + ",<seq2seq4repair_space>message:" ) + ( e . getMessage ( ) ) ) ) ; } } HttpConnectionMetrics metrics = ( ( HttpConnectionMetrics ) ( localContext . getAttribute ( HTTPHC4Impl . CONTEXT_METRICS ) ) ) ; long headerBytes = ( ( ( res . getResponseHeaders ( ) . length ( ) ) + ( httpResponse . getAllHeaders ( ) . length ) ) + 1 ) + 2 ; long totalBytes = metrics . getReceivedBytesCount ( ) ;

Fix:
throw new IllegalArgumentException ( ( ( "Unexpected<seq2seq4repair_space>method:<seq2seq4repair_space>'" + method ) + "'" ) ) ;